Systems and applications for tracking the gaze of a user are known. Typically, such systems include cameras and infrared illumination (IR) mounted proximate to a display and aimed at a user of the display. The IR illuminates the pupils of the eyes of the user and by computing the position and orientation of the eyes with respect to the display, an estimation of where the eye is looking can be derived. Such systems can be very expensive.
Eye-tracker systems generally have two aspects. First, these systems provide eye-tracking as a service, where the position of an element, in (x,y) co-ordinates, on a display that is currently being looked at by the user is available. Once the user focuses on the element, the eye movement is greatly reduced, which is known as a “fixation.” The second aspect is the requirement that eye tracker systems must be calibrated for each user because individuals respond differently to visual stimulation in terms of movement and orientation of their eyeballs.
While it may be straightforward to determine the position of the user's eyes with respect to a display, for any degree of accuracy the eye tracking data must be calibrated to take into account the individual user's eye performance. The conventional calibration procedure is to present to the user an otherwise empty display with a circle which moves around the screen to 5 fixed points then pausing and pulsating. This calibration procedure instructs the user to focus or fixate on the circle at each fixed point on the screen. During this procedure, the eye tracker measures characteristics of the user's eyes and uses them together with an internal, physiological 3D eye model to calculate the gaze data. This model includes information about shapes, light refraction and reflection properties of the different parts of the eyes (e.g. cornea, placement of the fovea, etc.). The problem with this calibration procedure is that it is visually boring, and more importantly, makes the user very aware that their eyes are being tracked.
Thus, what is needed is a system and method to perform the calibration processes required for tracking eye movement without a user being aware, and in a much more visually appealing manner. In this way, tracking may be used with gaming machines without the user knowing that an eye tracking calibration process is being performed.